There has been a lot of talk by a few people here about "total light", and how an f/1.4 lens on a m4/3 camera supposedly acts like an f/2.8 in regards to "light on the sensor", etc. No examples have been given in those threads, so I thought I would post some test shots I just did.

Panasonic GX1 with Canon FD 50mm f1.4

Canon 5D with EF 100mm f2.0

Both photos were taken at ISO 160, 1/250, f/2.0I have not edited the out of camera jpegs in any way. Other than slight differences in the magnification of the two lenses, WB, and the obvious DOF difference, the exposures are equivalent. They are the same. When I print both photos on 4x6, they look the same. "Total light on the sensor" is a meaningless concept. Exposure and density is not.